Sheet conveying devices for conveying a sheet in various kinds of apparatus such as an image forming apparatus are known in which a paper dust removal roller is provided in a sheet conveying path to remove paper dust that is adhered to a sheet. A sheet conveying device of this kind is known which employs an operation of removing paper dust off the paper dust removal roller with such a member as a sponge to maintain the efficiency of the paper dust removal to remove paper dust (e.g., see JP-A-2004-299810).
However, the paper dust occurring on a sheet is classified into paper dust produced by a sheet's rubbing against individual apparatus components and paper dust produced at the time of cutting the sheet into a desired size. The former paper dust is mainly fibers of cellulose or the like, and the latter paper dust is mainly powder of minerals such as calcium carbonate. The latter paper dust is produced more at ends (hereinafter also called “edges”) of a sheet in the direction (hereinafter also called “width direction”) perpendicular to a conveying direction of the sheet.
Therefore, where paper dust is wiped off a paper dust removal roller only by a sponge, paper dust of the latter kind is accumulated in wedge form between the sponge and the paper dust removal roller at positions corresponding to the edges of a sheet. Being powder of minerals, the thus-accumulated paper dust of the latter kind damages the surface of the paper dust removal roller as it rotates. As a result, conventionally, the durability of the paper dust removal roller cannot be increased sufficiently and hence the running cost of the sheet conveying device is increased.